The first test of how well prepared the United States is for a terrorist attack that could be deadlier than the attacks of September 11, 2001, is being conducted in Seattle, Washington. The five-day exercise will involve a simulated attack with biological and radioactive weapons.
The exercise, known as TOPOFF 2, begins with a simulated explosion of a "dirty-bomb," the kind of radiological device that U.S. officials have warned the terrorist network al-Qaida has been trying to acquire.
Actors will stand in for President George W. Bush, other top officials and attack victims. Thousands of real responders, from law enforcement to federal and local officials, will test and practice their ability to react to terrorist attacks.
"The exercise starts with some intelligence assessments that have been going on for several days," said Federal Emergency Management Agency Director Mike Brown.
Authorities across the border in Canada will also be taking part in the $16 million drill, which involves the city of Chicago later in the week. There, actors will begin showing up at hospitals with flu-like systems as that city tests how well it is able to respond to a simulated biological weapons attack.
Homeland Security officials say they want the exercise to be as real as possible.